a container with a lid, a handle, and a spout, used for boiling and pouring water [= teakettle American English]
She filled the kettle and switched it on.
The kettle's boiling (=the water in it is boiling).
Put the kettle on (=start boiling water in a kettle) will you?
2 American English
a large pot, used for making soup
used to say that a situation is very different from one that you have just mentioned:
She enjoys public speaking but being on TV is a different kettle of fish.